* {
    padding: 0;
    margin: 0;
}

img {
    width: 100%;
    height: 100%;
}

@function vw($vw) {
    @return $vw /750 *100+vw;
}

.wrap {
    width: 100vw;
    height: 100vh;
    background: url("../../img/首页\ -1.png") no-repeat;
    background-size: 100vw 100vh;
    background-position: center 0;
}